Currently, conference calling can involve geographically dispersed participants. For example, a conference call can be between participants on different continents, in different cities, etc. Commonly, a single media server having a mixer is used to facilitate the conference call. For example, each participant in the call is typically using a device (e.g., a smart phone, voice over IP phone, computer, etc.). When the device initiates connection to the conference call, a media server having a mixer is assigned to service the conference call. As each participant connects to the call, the mixer can allow all participants in the conference call to input audio to the mixer and to speak during the conference. The mixer can decide which participant's audio is output to each party.
Currently, service providers can have Session Border Controller (SBC), or other network border devices in physical data centers dispersed geographically throughout the world. Border devices comprise, routers, firewalls, network address translators (NAT), back-to-back User Agents, and combinations thereof such as a Session Border Controller (SBC). As is common in the art, these are connected to external networks as well as to internal private networks. Service providers (e.g. internet telephony service providers or traditional telecommunications carriers) can route calls through external networks to border devices, based on routing rules. The call can be routed from border devices to a media server within the internal network and they can connect to the conference. The internal network can be divided into subnets. Subnets may be organized according to geographic regions serviced by one or more data centers. Subnets may interface to external networks through border devices.
In a first example, the first participant to connect to the conference call is within the Northeast of the United States, and a media server within an internal subnet assigned to service the Northeast of the United States can act as the media server for the conference. As other participants of the conference call connect to the conference, regardless of where they are geographically located, the media server that was selected at the start of the conference call is the media server that services the duration of the conference call. Continuing with the example, if participants connect from Asia and Europe, the media server that services the Northeast continues to service the conference call.
If during the conference call any participant leaves the conference call, the initial media server continues to service the conference call. Continuing with the example, if the participant that resides in the Northeast of the United States leaves the conference, the media server that services the Northeast continues to service the conference call, even though there are no participants in the Northeast remaining on the conference call. This can cause unnecessary delay (e.g., latency) in the audio between the remaining parties due to the network distance needed for voice media to be transmitted across. Such delay is especially unnecessary if the remaining parties are from regions closer to each other than they are to the initial region.
Therefore, it can be desirable to minimize latency of a conference call for geographically proximal participants. Failure to minimize latency can result in unwanted effects such as audio echo and/or talk-over between the parties.